1. Field of the Invention
The present invention relates to an image forming apparatus as exemplified by a copier and a printer.
2. Description of Related Art
An electrophotographic image forming apparatus such as a copier or a printer incorporates a fixing section, where it fixes a toner image on paper by applying heat and pressure to the paper having the toner image transferred thereto. Heat is applied to the paper by the use of a fixing member such as a fixing roller or a fixing belt. This fixing member is kept in pressed contact with a pressing member such as a pressing roller or a pressing belt so that a fixing nip is formed in between through which to pass the paper to apply pressure thereto.
In the fixing section of the image forming apparatus described above, the contact between the fixing member and the paper is so intimate that the paper may fail to come off the fixing member. If the paper fails to come off the fixing member, it may jam around the exit of the fixing section and be exposed to a high temperature. To avoid this, a peel-off claw is commonly provided at the exit of the fixing section so that the paper is forcibly taken off the fixing member. Such a peel-off claw is effective in taking the paper off the fixing member, indeed, but, once the paper jams, the peel-off claw may become an obstacle that interferes with jam disposal. This inconvenience has led to the proposal of a construction that can cope with a paper jam when one occurs in the fixing section. Such a construction is proposed, for example, in Japanese Patent Application Laid-open No. 2000-19885 (hereinafter referred to as Patent Publication 1).
In the fixing unit disclosed in Patent Publication 1, a peel-off claw for taking paper off a heating roller (fixing member) is provided near the exit of a fixing section, and, when a paper jam ever occurs, the peel-off claw is retracted to a position where it does not interfere with jam disposal. Here, inconveniently, just on the downstream side of the fixing member and a pressing member, a paper discharge roller (fixing section discharge roller) is provided, and, even if the peel-off claw is retracted, the paper discharge roller can not. Thus, the paper discharge roller may interfere with jam disposal. This situation cannot be coped with by the user, causing great inconvenience to the user.